Ending Covid-19 Isolation
A friend messaged me the other day to inquire about a positive rapid antigen test (RAT). She tested positive for Covid nine days prior and had diligently isolated herself in a bedroom, away from her family. She re-tested on day 5, day 6, and day 7: still positive. And now, again, the ‘test’ line on her RAT test was positive on day 8. “Does the positive test mean I should keep isolating? And why is the isolation period five days if people really stay infectious longer?”, she asked.
The CDC revised its isolation guidelines in December 2021, stating that most people who test positive for Covid but have been fever-free for at least 24 hours can stop isolating after five days (with day 0 being the start of symptoms or, if asymptomatic, the date of the positive test) and did not need a negative coronavirus test to leave isolation. They do still recommend, though, that people continue taking precautions such as mask-wearing and refraining from travel on days 6 - 10.
A CDC study showed that up to half of people infected with Covid will continue to be infectious on days 6 - 9. Thus, although it is not mandatory, many people who have the option to are continuing to isolate until they receive a negative rapid antigen test (RAT). RAT tests correlate well with the amount of virus in the body and how likely you are to spread the virus to others.
It is important to remember that - in contrast to RATs - while polymerase chain reaction (PCR) tests are considered the gold standard for the initial diagnosis of Covid, they are not helpful in determining when to end isolation because they can remain positive for weeks to months after infection, well after a person has fully recovered and is no longer contagious.
Although it may have been more in line with the viral time course to continue recommending ten days of isolation, it is likely that the CDC recognized the burden the longer isolation period carried, with the greatest toll falling on the most vulnerable sectors. In fact, despite current CDC recommendations, Amazon just recently announced it would be ending its Covid-19 paid leave policy; it’s likely other large employers will soon follow suit.